Table 8: List of Stacking Terms (continued)
Term
Description
Standby node
A node that is prepared to become a backup node in the event that the
backup node becomes the primary node. When a backup node becomes a
primary node, the new primary node synchronizes all of its databases to
the new backup node.
When a node operates in a standby role, most databases are not
synchronized – except those few that directly relate to hardware
programming.
Acquired node
A standby or backup node that is acquired by a primary node. This means
that the primary node has used its databases to program the hardware of
the standby or backup node. The standby or backup node has acted as a
hardware programming proxy, accepting the instructions of the primary
node to do so.
An acquired backup node maintains the databases needed to reflect why
the hardware is programmed as it is. However, a standby node does not.
An acquired node can be re-acquired (without a reboot) by the backup
node only when the backup node becomes the primary node, and only
when both the backup and standby nodes were already acquired by the
same primary node at the time of its failure.
Data ports
The set of ports on a stackable switch that are available for connection to
your data networks. Such ports can be members of a user-configured
VLAN or trunk group. They can be used for Layer 2 and 3 forwarding of
user data traffic, for mirroring, or other features you can configure. Data
ports are different from stacking ports.
Failover
The process of changing the backup node to the primary node when the
original primary node has failed.
When a primary node fails, if a backup node is present, and if that node
has completed its initial synchronization with the primary node, then the
backup node assumes the role of primary node. The standby nodes
continue their operation and their data ports do not fail.
Hitless failover
A failover in which all data ports in the stack, except those of the failing
primary node, continue normal operation when the primary node fails.
Node address
The unique MAC address that is factory-assigned to each node.
Node role election
The process that determines the role for each node. The election takes
place during initial stack startup and elects one primary node and one
backup node. An election also takes place after a primary node failover,
when a new backup node is elected from the remaining standby nodes.
Node role election priority A priority assigned to each node, to be used in node role election. The
node with the highest node role election priority during a role election
becomes the primary node. The node with the second highest node role
election priority becomes the backup.
Operational node
A node that has achieved operational state as a card in a slot. The
operational state can be displayed using the
show slot {
slot
{
detail
} |
detail
}
command.
System uptime
The amount of time that has passed since the last node role election. You
can display the system uptime by entering the
show switch
{
detail
}
command on the primary node.
Build Stacks
SummitStack Terms
ExtremeSwitching 5320 Series Hardware Installation Guide
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